[PATCHv2 3/4] mm: vmalloc: add VM_DMA flag to indicate areas used by dma-mapping framework
From: minchan@kernel.org (Minchan Kim)
Date: 2012-05-22 07:07:47
Also in:
linux-mm, lkml
On 05/17/2012 07:54 PM, Marek Szyprowski wrote:
quoted hunk ↗ jump to hunk
Add new type of vm_area intented to be used for consisten mappings created by dma-mapping framework. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com> --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 3 +++ 2 files changed, 4 insertions(+)diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 6071e91..8a9555a 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h@@ -14,6 +14,7 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */ #define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */ #define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */ #define VM_UNLIST 0x00000020 /* vm_struct is not listed in vmlist */ +#define VM_DMA 0x00000040 /* used by dma-mapping framework */ /* bits [20..32] reserved for arch specific ioremap internals */
quoted hunk ↗ jump to hunk
/*diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 8cb7f22..9c13bab 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c@@ -2582,6 +2582,9 @@ static int s_show(struct seq_file *m, void *p) if (v->flags & VM_IOREMAP) seq_printf(m, " ioremap"); + if (v->flags & VM_DMA) + seq_printf(m, " dma"); +
Hmm, VM_DMA would become generic flag? AFAIU, maybe VM_DMA would be used only on ARM arch. Of course, it isn't performance sensitive part but there in no reason to check it, either in other architecture except ARM. I suggest following as #ifdef CONFIG_ARM #define VM_DMA 0x00000040 #else #define VM_DMA 0x0 #end Maybe it could remove check code at compile time.
if (v->flags & VM_ALLOC) seq_printf(m, " vmalloc");
-- Kind regards, Minchan Kim